ParseRelation#query - Unhandled Exception: type 'ParseObject' is not a subtype of type *

[kutear]

New Issue Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.
• I can reproduce the issue with the latest version of Parse Server and the Parse Flutter SDK.

Issue Description

When i get a ParseRelation(relation) from a subClass of ParseObject, then build a QueryBuilder(queryBuilder) by relation.getQuery(), and invoke builder.query<Wallet>() to get a response. at this time i get some error.

E/flutter ( 7948): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: type 'ParseObject' is not a subtype of type 'Wallet'
E/flutter ( 7948): #0      _ParseResponseBuilder._handleSuccess (package:parse_server_sdk/src/objects/response/parse_response_builder.dart:93:59)
E/flutter ( 7948): #1      _ParseResponseBuilder.handleResponse (package:parse_server_sdk/src/objects/response/parse_response_builder.dart:29:14)
E/flutter ( 7948): #2      handleResponse (package:parse_server_sdk/src/objects/response/parse_response_utils.dart:8:31)
E/flutter ( 7948): #3      ParseObject.query (package:parse_server_sdk/src/objects/parse_object.dart:419:14)

Steps to reproduce

    class Plan extends ParseObject {
    ...
    }

    final plan = ...;
    ParseRelation<Wallet> relation = plan.getRelation("wallets");
    QueryBuilder builder = relation.getQuery();
    final response = await builder.query<Wallet>();
    if (response.success) {
      // do something
    }

Actual Outcome

Unhandled Exception: type 'ParseObject' is not a subtype of type 'Wallet'

Expected Outcome

query success and get a list of Wallet

Environment

  parse_server_sdk_flutter: 3.1.0

Parse Flutter SDK

• SDK version: 3.1.0
• Operating system version: android

Server

• Parse Server version: 3.1.0

Logs

None

[parse-github-assistant]

Thanks for opening this issue!

• 🚀 You can help us to fix this issue faster by opening a pull request with a failing test. See our Contribution Guide for how to make a pull request, or read our New Contributor's Guide if this is your first time contributing.

[kutear]

other BUG

    final plan = ...;
    ParseRelation<Wallet> relation = plan.getRelation("wallets"); // This will be ok
    relation.add(someWallet); // or plan.addRelation("wallets", [someWallets]); 
    ParseRelation<Wallet> relation = plan.getRelation("wallets"); // Bad  

 Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'ParseRelation<ParseObject>?' in type cast

ParseObject#addRelation will modify the type of value _objectData['wallets'].

[kutear]

other BUG

    final plan = ...;
    ParseRelation<Wallet> relation = plan.getRelation("wallets"); // This will be ok
    relation.add(someWallet); // or plan.addRelation("wallets", [someWallets]); 
    ParseRelation<Wallet> relation = plan.getRelation("wallets"); // Bad  

 Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'ParseRelation<ParseObject>?' in type cast

ParseObject#addRelation will modify the type of value _objectData['wallets'].

Is my usage wrong? The ParseObject's _objectData is terrible, sometime it's include key - value, sometime it's include key - operation command.

Parse-SDK-Flutter/packages/dart/lib/src/objects/parse_base.dart

Lines 188 to 204 in 1114232

	/// Sets type [T] from objectData
	///
	/// To set an int, call setType<int> and an int will be saved
	/// [bool] forceUpdate is always true, if unsure as to whether an item is
	/// needed or not, set to false
	void set<T>(String key, T value, {bool forceUpdate = true}) {
	if (_getObjectData().containsKey(key)) {
	if (_getObjectData()[key] == value && !forceUpdate) {
	return;
	}
	_getObjectData()[key] =
	ParseMergeTool().mergeWithPrevious(_unsavedChanges[key], value);
	} else {
	_getObjectData()[key] = value;
	}
	_unsavedChanges[key] = _getObjectData()[key];
	}

Is it necessary to save data to _getObjectData()['key']?
And it's probably to save data to _unsavedChanges['key']? just like this,

  void set<T>(String key, T value, {bool forceUpdate = true}) {
    // if (_getObjectData().containsKey(key)) {
    //   if (_getObjectData()[key] == value && !forceUpdate) {
    //     return;
    //   }
    //   _getObjectData()[key] =
    //       ParseMergeTool().mergeWithPrevious(_unsavedChanges[key], value);
    // } else {
    //   _getObjectData()[key] = value;
    // }
    _unsavedChanges[key] = ParseMergeTool().mergeWithPrevious(_unsavedChanges[key], value);
  }

[juriSacchetta]

Hey guys,
I got this error.
I spend two hours to be sure can it was not my fault, and after I found this issue.

Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'ParseRelation<ParseObject>?' in type cast

I downloaded the repo and tried to see if the bug was been resolved, but unfortunately, it isn't.

I tried both the HEAD and #762 versions of the code, but nothing worked.

Can you help me?

Thanks a lot for your work!

    final plan = ...;
    ParseRelation<Wallet> relation = plan.getRelation("wallets"); // This will be ok
    relation.add(someWallet); // or plan.addRelation("wallets", [someWallets]); 
    ParseRelation<Wallet> relation = plan.getRelation("wallets"); // Bad  

 Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'ParseRelation<ParseObject>?' in type cast

[Nidal-Bakir]

Fix via #860